Conventionally, U-shaped guide rails for guiding rollers rolling therein are used to guide vehicle seats within a vehicle, wherein the guide rails run parallel to one another and are fixed to the body of the vehicle and the rollers are connected to a seat frame of the vehicle seat. Alternatively, the guide rails may already be integrated in the seat frame.
Such guide arrangements necessarily require the provision of an intermediate space between an inner side of the U-shaped profile of the guide rail and a bearing surface of the roller rolling therein, since the rolling directions of the roller on the upper and lower side in a given movement direction of the roller are opposed. This means that a rolling movement of the roller within the guide rail is possible only when the roller bears against one of the sides of the guide rail, namely the lower side or the upper side thereof. Otherwise, if both the upper side and the lower side of the guide rail were to bear against the roller, only a sliding movement of the roller within the guide rail would be possible, but not a rolling movement. On account of the necessary intermediate space, a play between guide rails and rollers arises, particularly after long-term use of the vehicle seat. Added to this is the fact that, in such roller guides, only small axial forces, that is to say forces acting laterally on the guide rail, can be absorbed by the rollers. This often results in one-sided wear of the rollers when axial forces occur. This gives rise to undesirable play between rollers and guide rail in the axial and radial direction.
U.S. Pat. No. 6,264,180 B1 discloses a roller guide for adjustable vehicle seats, in which two individual rollers or one roller split into two are/is fitted to each end of each axle of a seat frame of the vehicle seat, which roller or rollers can be adjusted by means of an adjustment mechanism with regard to their axial spacing from a guide rail in which they roll. The rollers are designed as cylindrical rollers and, when acted upon by axial forces, press against an inner end wall of the guide rail, so that the axial forces are absorbed exclusively by the inner end wall. This leads to undesirable friction forces and to undesirably high wear of this inner wall and of the rollers pressing against it.
Accordingly, it is an object of the present invention to provide a roller guide for adjustable vehicle seats, which allows play-free and virtually wear-free rolling of rollers within guide rails.